Appears to be a Mason coin. The initials represent someone who has attained the level of Royal Arch Mason. These letters could also appear on headstones.
Here is a link, but I did not find your specifically. http://cashcoinconnection.com/Casino/USA/CA/Fraternal/MASONIC.pdf
I think you will find (from examining Google images) that all Masonic pennies have the same initials: SSTKSHTW. I did find one reference which claims it means "HIRAM, TYRIAN, WIDOW'S SON, SENDETH TO KING SOLOMON," implying that you should start reading at the H. Don't know.
Is the OP's token the same size and weight as a US Large Cent? The few Masonic pennies I have in my token collection are all closer to the size of a half dollar.
i have never seen this kinda before, the keystone is normal, some have the city and such on them some do not. the side it says one penny on i think is interesting